Express server with TypeScript

Express is a popular web application server in JavaScript.

Let’s create a really quick and simple expression server which will be a good starting point for further posts which use this library.

I’ll assume you’ve created a folder, run yarn init and tsc –init, next up run

  • yarn add express
  • yarn add -D @types/express
  • Add a new file, mine’s named server.ts
  • Add the usual scripts 
    "scripts": {
  "build": "tsc",
  "start": "node server.js"
}

The code to run up a really simple server is as follows

import express from "express";

const server = express();

server.get("/", (request, response) => {
  response.send("<h1>Hello World</h1>");
});

const port = 4000;
server.listen(port, 
  () => console.log(`Server on port ${port}`)
);

Using our scripts, run yarn build followed by yarn start. The server should start on port 4000, so now navigate to http://localhost:4000 using your preferred browser and that’s it.

We’ve created a server instance on port 4000, we’re routed any root (i.e. /) calls to the response, which in this case returns a simple HTML string.